A new project group 11ai is established in the IEEE (Institute of Electrical and Electronics Engineers) 802.11, and the main object of this project group is to achieve simultaneous setup of fast initial link between many STAs (station, terminal/station point) and an AP (Access Point) in a wireless local area network when the STAs enter the coverage area of the AP, and the need of the putting forward the project group is to set up initial link between 100 STAs and the AP in one second.
A current process of initial link between the STA and the AP totally comprises about 13 steps, as specifically shown in FIG. 1. The current initial link setup manner cannot meet the needs of the 11ai, thus should be changed. Being different from a current AP, an AP supporting an FILS (Fast Initial Link Setup) function can set up initial link with an STA supporting the FILS function in a new faster mode.
In this way, a problem will be rendered that, if an STA which does not support the FILS function enters a WLAN (Wireless Local Area Network) network supporting the FILS function, if the process of setting up the initial link follows the FILS function mode, the STA which does not support the FILS function cannot analyze a network access instruction issued by the AP in the WLAN supporting the FILS function, and vice versa, an STA supporting the FILS function cannot set up fast initial link with an AP that does not support the FILS function in the FILS manner.
Therefore, a new technical solution is desired to solve the network incompatibility problem that an STA cannot be connected with an AP in the WLAN when an STA that does not support the FILS function enters a WLAN network which supports the FILS function and an STA that supports the FILS function enters a WLAN that does not support the FILS function.